Process of making flowable hemostatic compositions and devices containing such compositions

ABSTRACT

The present invention includes both sterilized and unsterilized hemostatic compositions that contain a continuous, biocompatible liquid phase having a solid phase of particles of a biocompatible polymer suitable for use in hemostasis and which is substantially insoluble in the liquid phase, and a discontinuous, biocompatible gaseous phase, each of which is substantially homogenously dispersed throughout the continuous liquid phase, methods for making such compositions, medical devices that contain sterilized hemostatic compositions disposed therein and methods of making such devices.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a Continuation of U.S. Ser. No. 10/768,335 filedJan. 30, 2004 and International Application PCT/US2004/023779, filed 23Jul. 2004, which claims priority from U.S. Provisional Application Ser.No. 60/493,116 filed Aug. 7, 2003.

FIELD OF THE INVENTION

The present invention relates to methods of making flowable hemostaticcompositions and devices containing such compositions.

BACKGROUND OF THE INVENTION

Gelatin-based hemostats, both in solid sponge or powder form, arecommercially available and are used in surgical procedures. Gelatinpowder, when mixed with fluid, can form a paste or slurry that is usefulas a flowable, extrudable and injectable hemostat for diffuse bleeding,particularly from uneven surfaces or hard to reach areas. Theconventional slurry is prepared at the point of use by mechanicalagitation and mixing of the powder and liquid to provide uniformity ofthe composition. The paste then is placed into a delivery means orapplicator, e.g. a syringe, and applied to the wound.

The main disadvantage of this approach is the need to mix the powderwith the liquid, knead it into a paste and back-fill it into thedelivery device of choice, all at the time of need and at the point ofuse. The manipulations are time consuming and potentially may compromisethe sterility of the delivered product depending on the environment ofuse. Thus, a need exists for a sterile, flowable, hemostatic compositionthat is ready to use at the point of use or can be prepared with minimalmanipulation and without risk of compromising the sterility of theproduct.

It would be desirable if a hemostatic device, e.g. a delivery means suchas a syringe or other applicator, would be pre-filled with a hemostaticcomposition and available to the surgeon at the point of use withoutneed for further manipulation or with minimal manipulation orpreparation. The hemostatic composition pre-filled in the device orapplicator should be sterile and flowable and should require minimumpreparation time and minimal force when extruded or injected through thedelivery means at the point of use. It also would be desirable to deviseprocesses for making such compositions that are commercially viable,maintain an acceptable environment in the work place and provide apre-filled device comprising a hemostatic composition that is flowableand physically stable. The present invention provides such processes.

SUMMARY OF THE INVENTION

The present invention is directed to processes of making flowablehemostatic compositions and devices that are suitable for use inapplying such flowable hemostatic compositions and that comprise theflowable hemostatic composition disposed therein. In a process formaking the flowable hemostatic composition, a first volume of abiocompatible liquid is introduced into a mixing vessel equipped with ameans for mixing the liquid. A second volume of a biocompatible gas isintroduced into the volume of liquid while the means for mixing isoperating under conditions effective to mix the liquid and the gastogether to form a foam. The foam comprises a discontinuous gas phasecomprising the gas dispersed throughout a continuous liquid phasecomprising the liquid. An amount of solid particles of a biocompatiblepolymer suitable for use in hemostasis and which is substantiallyinsoluble in the liquid is introduced into the foam and the foam and thesolid particles are mixed together under conditions effective to form asubstantially homogenous composition comprising the discontinuous gasphase and the solid particles substantially homogenously dispersedthroughout the continuous liquid phase. The ratio of the volume ofliquid, volume of gas and amount of solid particles is effective toprovide the hemostatic composition with hemostatic properties, thusforming the flowable hemostatic composition. The flowable hemostaticcomposition so formed is then transferred into a device suitable forapplying the flowable hemostatic composition to a site of a bodyrequiring hemostasis under conditions effective to maintain thesubstantially homogeneous dispersion of the gas phase and the solidparticles throughout the liquid phase. The device comprising theflowable hemostatic composition disposed therein is subjected, orexposed, to conditions effective to provide a sterile device comprisinga sterile, flowable hemostatic composition. Compositions and devicesmade by the processes of the present invention may be prepared well inadvance of the time of use and need not be prepared at the point of use,yet they maintain physical properties effective to provide flowability,extrudability or injectability at the point and time of use.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a schematic cross-sectional side view of a mixing apparatusused in processes of the present invention.

FIG. 2 is a schematic cross-sectional side view of a filling apparatusused in processes of the present invention.

FIG. 3 is a side perspective view of an auger screw of the type used inprocesses of the present invention.

FIG. 4 a is a side elevation view of an apparatus used in processes ofthe present invention.

FIG. 4 b is a cross-sectional side view of an apparatus used inprocesses of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

Both sterilized and unsterilized compositions made by processes of thepresent invention contain solid, porous or non-porous particles of abiocompatible polymer suitable for use in hemostasis, a biocompatibleliquid and a biocompatible gas as its three necessary components. Theparticles, liquid and gas are combined and mixed under conditionseffective to provide a substantially homogeneous hemostatic compositioncomprising a continuous liquid phase comprising the liquid, and thesolid polymer particles and a discontinuous gas phase comprising the gashomogenously dispersed through the continuous liquid phase. The amountand average diameter of particles contained in the composition and therelative amount of the solid, liquid and gaseous phases is effective toprovide the composition with hemostatic and physical properties, asdescribed herein below.

The hemostatic composition so formed is a hemostatic paste, or slurry,that exhibits improved properties of flowability, extrudability and/orinjectability when compared to flowable hemostatic compositions ofsimilar liquid/particle composition but that do not contain a gaseousphase dispersed therethrough. Compositions made by the processes of thepresent invention may be prepared, filled into a medical device, such asa syringe or other known applicators used to dispense flowablehemostatic compositions, and sterilized by ionizing irradiation, well inadvance of the time of their intended use. The compositions further mayinclude additives to facilitate the preparation of the composition,enhance physical and mechanical properties, enhance the hemostaticproperties of the composition, or provide antimicrobial properties.

As used herein, “continuous” and “discontinuous” are used in theordinary meaning of those words in the context of standard nomenclatureused to define and describe dispersions. For example, when combined andmixed with the continuous liquid phase, the volume of biocompatible gasadded to the liquid phase is disrupted by mixing so as to form thediscontinuous, i.e. dispersed, gaseous phase comprising pockets orisolated bodies of gas.

As used herein, “substantially homogenous” denotes that physical stateof the compositions or pastes where the solid and/or gaseous phases areuniformly dispersed throughout the continuous liquid phase such that theratio of solid:gas:liquid and the density of any portion orcross-section of the composition or paste are substantially the same.

As used herein, “foam” denotes that state where the discontinuous gasphase has been dispersed in the continuous liquid phase. The gas phasein the foam need not be substantially homogenously dispersed through thefoam.

As used herein, “density” is used in the ordinary meaning of the word inthe context of standard nomenclature used to define and describe themass of the mixture of the solids and the added liquid per unit volumeof the foamed paste.

As used herein, “sterile” means substantially free of living germsand/or microorganisms and as further recognized and described bygovernmental standards pertaining to compositions and medical devicesdescribed and claimed herein. As used herein, “hemostatic”, or“hemostatic properties”, means the ability to stop or minimize bleeding,as one skilled in the art of hemostasis would understand those terms tomean, as further exemplified in the examples of the specification.

As used herein, “peak expression force” is the peak force value requiredto extrude compositions from a pre-filled luer syringe fitted with a 14gauge angiocatheter tip, as described in the examples of thespecification.

A variety of biocompatible natural, semi-synthetic or synthetic polymersmay be used to prepare the solid particles used in compositions of thepresent invention. The polymer selected must be substantially insolublein the liquid chosen for the particular composition. Preferably,water-insoluble biodegradable polymers that provide mechanical, chemicaland/or biological hemostatic activity are used. Polymers that may beused include, without limitation, proteins and polysaccharides.Polysaccharides that may be used include oxidized cellulose, chitosan,chitin, alginate, oxidized alginate and oxidized starch. Thebiocompatible polymer used to prepare the particles preferably is across-linked or denatured protein, such as gelatin, collagen, fibrinogenor fibronectin. A preferred gelatin powder is a partially cross-linkedgelatin powder prepared by milling gelatin sponge into particles havingan average diameter of from about 40 microns to about 1200 microns, orfrom about 100 microns to about 1,000 microns, as determined by laserdiffraction.

Compositions made by processes of the present invention comprise acontinuous liquid phase in which the solid particles and gaseous phaseare substantially homogenously dispersed. Depending upon the particularmedical device and use thereof, the liquid may be aqueous ornon-aqueous. In certain embodiments, the liquid phase is aqueous.Aqueous liquids may include, without limitation, biocompatible aqueoussolutions, such as calcium chloride and saline. More preferably, theliquid phase comprises saline. The liquid phase and solid particulatephase are present in relative amounts effective to provide a paste, orslurry, suitable for use in providing hemostasis. Excessive dilution ofthe solid particulate phase, although beneficial to further reduce thepeak expression force, will detrimentally affect the hemostaticproperties of the material and therefore is not desired. The weightratio of solid particles to liquid generally is from about 1:2 to about1:12. In certain embodiments the weight ratio of solid gelatin particlesto saline is from about 1:3 to about 1:6. In yet other embodiments theweight ratio of solid gelatin particles to saline is about 1:5.

Any biocompatible gas may be used to prepare compositions of the presentinvention, including, but not limited to, air, carbon dioxide, nitrogen,xenon or argon. Preferably an inert gas such as argon or nitrogen isused. Air, nitrogen and argon are sensitive to ultrasound and mayprovide a means to locate the composition once injected in the body.Similarly, as xenon is radio-opaque, using xenon also may provide ameans to locate the composition once placed in the body. In addition, ascarbon dioxide lowers pH, selection of carbon dioxide may enhanceantimicrobial properties of the compositions. The gas is combined andmixed with the continuous liquid phase until it is dispersed throughoutthe liquid phase so as to form a discontinuous gaseous phase dispersedin the continuous liquid phase so as to form a foam. Upon formation ofthe composition by dispersion of the particles in the foam, thedispersion of the gas phase in the composition provides the compositionwith improved physical properties relating to flowability, extrudabilityand injectability, as described herein. Such improved properties arecharacterized by way of physical measurements of the compositions,including density and peak expression force, both prior to and afterirradiation of the compositions during sterilization.

The relative concentration of the three major components of thecompositions of the present invention and the substantially homogenousnature of such compositions are key in providing both hemostatic andphysical properties to the compositions. The solid particles, liquidphase and gaseous phase generally will be present in compositions madeby processes of the present invention at a ratio of from about 1:2:1 toabout 1:12:13, based on weight:volume:volume (g:ml:ml). In otherembodiments the ratio will be from about 1:4:1 to about 1:8:9. In yetother embodiments the ratio will be about 1:5:3. The density ofcompositions of the present invention will be from about 0.9 g/ml toabout 0.3 g/ml, or in certain embodiments from about 0.8 g/ml to about0.6 g/ml.

Certain compositions made by the processes of the present inventiondescribed herein are sterile, in that they have been irradiated with alevel of, e.g. ionizing irradiation. Such irradiation may include e-beamor gamma irradiation. The level of irradiation and conditions ofsterilization, including the time that the compositions are irradiated,are those that provide sterile compositions, as defined herein. Oncehaving the benefit of this disclosure, one skilled in the art will beable to readily determine the level of irradiation necessary to providesterile compositions.

The hemostatic compositions may further comprise effective amounts ofone or more additives or compounds including, but not limited to, radioopaque agent, antimicrobial agents, foaming agents, foam stabilizers,surfactants, antioxidants, humectants, wetting agents, lubricants,thickeners, diluents, irradiation stabilizers, e.g. radical scavengers,plasticizers, and stabilizers. For example, glycerol may be added toenhance the extrudability or injectability of the composition. Glycerolmay be present in the compositions up to about 20% by weight, or fromabout 1% to about 10%, or from about 1% to about 5%, based on the weightof the liquid phase. In addition, quaternary amines may be used toprovide enhanced properties to the compositions. For example,benzalkonium chloride, Polybrene or Onamer M may be used at levels up toabout 1 percent by weight, based on the weight of the liquid phase. Incertain embodiments benzalkonium chloride is used at levels of fromabout 0.001% to about 0.01%, or from about 0.002 to about 0.006% byweight, based on the weight of the liquid phase. It is believed that thequaternary amines may serve multiple functions, acting as anantimicrobial agent, a foaming agent, a radical scavenger and/or as aheparin neutralizer.

Such hemostatic compositions may further comprise effective amounts ofheparin neutralizers, procoagulants or hemostatic agents, such asthrombin, fibrinogen, fibrin, Factor Xa, or Factor VIIa. By “effectiveamount”, it is meant that amount necessary to provide to thecompositions those properties for which the additive is being added. Themaximum amount that may be added is limited so as not to causedetrimental biological affects.

Compositions made by processes of the present invention are particularlyadvantageous for use in hemostatic compositions where additives that aresensitive to irradiation, are utilized. For example, thrombin, in anaqueous solution, has been found to lose all procoagulant activity whenexposed to sterilization irradiation. In contrast, thrombin retainedapproximately 40% of its original enzymatic activity and all of itshemostatic activity after sterilization when formulated in compositionsaccording to this invention, as shown in Example 9. While bovinethrombin is exemplified herein, human-derived thrombin such as describedin U.S. Pat. No. 5,143,838, the content of which is hereby incorporatedby reference herein in its entirety, also may be used in compositions ofthe present invention.

Medical devices in which the hemostatic compositions of the presentinvention may be utilized include any device currently being used toapply a flowable or injectable hemostatic paste or slurry to a site, orwound, requiring hemostasis. The site requiring hemostasis may be theresult of an injury or a surgical procedure. Examples of devices orapplicators include syringes such as Becton Dickinson or Monoject luersyringes. Other devices are disclosed in detail in U.S. Pat. No.6,045,570, the contents of which are incorporated by reference in theirentirety.

In processes of the present invention, the liquid is added to the mixer.The gas then is incorporated into the liquid with mixing underconditions effective to form a foam comprising a discontinuous gas phaseof the gas dispersed through a continuous liquid phase of the liquid. Incertain embodiments the gas and liquid may be mixed for from about 3 toabout 30 minutes. The solid polymer particles are then incorporated intothe foam and mixed so as to substantially homogenously disperse thesolid particles throughout the foam. In certain embodiments the foam andparticles may be mixed for from about 15 to about 30 minutes, althoughmixing for more than 30 minutes is acceptable. In such embodiments amixer, e.g. a double planetary mixer, may be utilized.

The liquid may include effective amounts of additives dissolved thereinprior to addition of particles or the gas to the solution. For example,a saline solution containing glycerol and benzalkonium chloride may beprepared and then added to the mixer. A source of gas is provided to themixer whereby a first portion of the gas may be added to the liquidsolution. The mixture of gas and liquid is mixed to disperse the gas inthe liquid phase, thus forming a foam. The solid particles and anyadditional portion of gas then are added to the mixer over time withcontinuous mixing until all ingredients have been added. The mixing iscontinued until such time as a substantially homogenous composition isformed containing the solid particles and discontinuous gaseous phaseuniformly dispersed throughout the continuous liquid phase. The densityof the mixture of liquid, gas and solid particles may be monitored todetermined at what point the composition is substantially homogeneous soas to provide the composition with desired physical and hemostaticproperties.

The flowable hemostatic compositions so formed are then transferred intoa device suitable for applying the flowable compositions to a site ofthe body requiring hemostasis. The filled device and compositioncontained therein then are sterilized to provide a sterile, ready-to-usesystem that avoids issues of the current state of the art with regardsto on-site preparation and handling just prior to use.

While preparation of compositions and devices noted above may be readilyachieved on a small scale, such as a laboratory setting, the preparationof such compositions and devices on a scale suitable for commercial usepresents additional issues.

In a commercial manufacturing setting, certain issues not readilyapparent in the small scale preparation of compositions and devices mustbe addressed, including the general environment of the workplace,potential increased bioburden of the solid particles due to exposure tothe atmosphere, and maintaining the physical structure and properties ofthe compositions during transfer to the applicator devices andsterilization. For example, when a large quantity of fine particles inthe form of a powder are added to a mixing vessel, the fine particlesize of the particles in the powder may cause excessive dusting in theworkplace, which may create environmental concerns, including issuesrelated to personnel safety and general maintenance of the workplace, aswell as the qualification grade of the facility. Additionally, gelatinbased materials, for example, when exposed to the environment for aprolonged period of time, may be subject to infestation bymicroorganisms. The increased bioburden of the powder may lead todegradation of the gelatin during processing and may be detrimental tothe sterility and biocompatibility of the product.

In order to minimize the environmental issues that may be caused byexcessive dusting, one solution may be to compact or condense theparticles into a physical body, such as pellets, granules or any otherappropriate shape prior to the mixing. The body of particles may, butneed not, comprise a plurality of packed particles comprisinginterstitial pores having a pore volume and a median pore diametereffective to provide improved absorption of an aqueous media into theinterstitial pores when placed in contact therewith, compared to aplurality of unpacked particles.

Alternately, the solid particles may be added to the mixing vesselcontaining the foam through a structure or conduit that is closed orsealed so as to avoid exposure of the powder particles to the atmosphereduring addition. Adding the particles via such a structure minimizesdusting caused by the addition of fine particles, as well as reduces theopportunity for the growth of microorganisms on the residual particlespreviously trapped on the inner wall of the mixing vessel prior toincorporation.

In addition to environmental issues as discussed above, transfer of theflowable hemostatic compositions from the mixing vessel to the medicaldevices may lead to the breakdown or deformation of the physicalstructure of the composition, i.e. disruption of the dispersion of thesolid particles and gas phase throughout the liquid phase. If one wereto attempt to transfer the substantially homogenous hemostaticcomposition from the mixing vessel to the applicator device byrelatively high pressure, it may be difficult to maintain the structureof the hemostatic composition due to compression forces that may arisedue to the relatively high pressure required to move the paste in suchinstances. Such compression could lead to separation of the gaseousphase from the liquid phase. Such a loss of the gaseous phase isdetrimental to the mechanical properties of the composition, e.g.flowability and ease of mixing, both during and after the irradiationprocess.

The processes of the present invention minimize such detrimental effectsby transferring the composition throughout the process under conditionsthat avoid the creation or presence of appreciable pressures that maylead to compression forces. Preferably, the composition is transferredfrom the mixing vessel into the applicator device in the substantialabsence of such compression forces and under minimal pressureconditions, meaning those conditions that provide for efficient transferof the composition without detrimentally affecting the structure of thecomposition.

In order to maintain minimal pressure conditions, certain embodiments ofprocesses of the present invention utilize an auger screw to transferthe hemostatic composition into the applicator device. In certainembodiments exemplified herein, the auger screw is used in a verticalorientation to take advantage of gravitational forces for filling thedevices, although it is contemplated that transfer of the compositionfrom the mixing vessel to a filling apparatus could be conducted with ahorizontal screw orientation. The auger screw provides for localmovement of the compositions through the process versus bulk transfer.In this way, large forces applied to the bulk of the composition thatmay lead to compression on the whole of the body of material may beavoided in lieu of localized forces within the body of material.

As the compositions prepared according to the present invention comprisegaseous, liquid and solid phases, as described above, maintaining thestructure of the composition will depend in part on the design of theauger screw. To maintain the structure and ratios of liquid:gas:solidparticles of the compositions within acceptable parameters, and thus thedensity of the extruded hemostatic paste within an acceptable densityrange, considerations for an auger design include the width, number andpitch of the flights on the auger screw, the angle of the flight to theauger screw rod, the design and finish of the auger bowl, the diameterand angle of the agitator blade and on the overall scale of theapparatus.

Once transferred into the holding vessel of the filling apparatus,maintaining conditions effective to maintain the structure of thecompositions during filling will depend on a number of aspects. Oneconsideration is the amount of work that may be imparted to thecompositions either by the auger screw or by gravitational forcesexerted on the bulk of the composition. The resident time of thecompositions within the filling apparatus is related to each of theseconsiderations. The longer the composition is held within the fillingapparatus, the longer it is subjected to repetitive, pulsing forcescreated by the auger screw during filling and the longer it has to havethe weight of the body of the composition act to compress thecomposition itself, each of which may lead to separation of the gasphase from the liquid phase. In addition, the configuration and finishof the auger bowl must be considered. Surface finishes that minimizefriction between the material and the sides of the auger bowl willminimize any detrimental effects that may be caused by friction.

It was found that the resident time of the compositions in the fillingapparatus, the overall work imparted to the compositions and the rate oftransferring the compositions into the applicator device may beoptimized such that the adverse effects, as stated above, may beminimized. With respect to specific embodiments exemplified herein, itwas found that the rate of transfer of the composition from the holdingvessel of the apparatus to the devices advantageously is at least about12 ml/minute, or at least about 36 ml/minute, or even about 72ml/minute, and even more than about 100 ml/minute. It will be understoodby those skilled in the art that the actual rate at which thecomposition is transferred in order to optimize resident time workimparted to the composition, however, will depend upon the particulardesign and size of the filling apparatus, as well as the particularcomposition being filled.

As shown in FIG. 1, mixing apparatus 10 includes mixing vessel 12,equipped with mixing means 14. Mixing means 14 comprises multiplehelical blades 16 that rotate on their own axes, while orbiting mixingvessel 12 on a common axis. Helical blades 16 continuously advancearound the periphery of mixing vessel 12, removing material frominternal mixing vessel wall 18 and transporting to the interior ofmixing vessel 12, thus allowing the entire batch of materials to bemixed thoroughly. Mixing vessel 12 is fit with mixing vessel cover 36 soas to provide a closed system. Mixing cover 36 includes addition ports24, 30 and 34 for addition of liquid 22, gas 40 and solid particles 26into mixing vessel 12. Hopper 28 containing solid particles 26 is in aclosed relationship with mixing vessel cover 36 via conduit 32 includingpowder flow regulating valve 38 to minimize exposure of solid particles26 from the atmosphere.

In one embodiment of the process, liquid 22 is added to mixing vessel 12via port 24. Mixing means 14 is engaged at a rate of from about 60 toabout 80 Hz to facilitate mixing of gas 40 and liquid 22 when the twoare placed together. Gas 40 is introduced into liquid 22 in mixingvessel 12 via port 34. Liquid 22 and gas 40 are mixed at a rate and fora time effective to provide a foam as described herein above. Solidparticles 26 are then introduced into the foam via conduit 32. The foamand solid particles 26 are then mixed at a rate and for a time effectiveto substantially homogenously disperse particles 26 throughout the foam.Once prepared, the flowable hemostatic composition is transferred to aholding vessel of a filling apparatus shown in FIG. 2 for subsequentfilling into an applicator device. The transfer of the hemostaticcomposition to the holding vessel may be conducted manually, e.g., byusing a sterile scoop, as described herein, or by any automated means.

As shown in FIG. 2, filling apparatus 40 includes holding vessel 42 forholding flowable hemostatic composition 44 and auger screw 46 disposedwithin holding vessel 42 and auger funnel 48 and in cooperation withmotor 54 and agitator blade 49 in cooperation with motor 47. Auger screw46 transports flowable hemostatic composition 44 from holding vessel 42and through auger funnel 48 in a downward spiral fashion. Agitator blade49 serves to prevent material from building on the walls of the holdingvessel while also maintaining the homogenous structure of thecomposition during filling. Flowable hemostatic composition 44 then istransferred into applicator device 52 via exit port 50. As composition44 is filled into devices 52, 56, 58, auger screw 46 is in operation toaffect transfer. After device 50 is filled, operation of auger screw 46is disrupted and the stream of the composition separated to provide forsubsequent filling of additional devices 56 and 58. The repeateddisruption of flow creates a pulsating force upon composition 44 withinholding vessel 42. This repeated mechanical manipulation of thecomposition may detrimentally affect the composition properties. Thus,as discussed above, the design of auger screw 46 and the rate of fillingdevices 52, 56 and 58 are optimized to minimize negative effects.

An auger screw of the type that may be used in processes of the presentinvention is shown in FIG. 3. As shown, screw 60 comprises multipleflights 62, 64 attached to auger screw rod 66. As shown, flight 62 has agreater diameter than flight 64. In embodiments of the presentinvention, the number, diameter, angle and distance between fights maybe designed to accommodate particular apparatus being used or thecomposition itself. One skilled in the art will be able to readilyascertain other screw designs that may be employed in processes of thepresent invention once having the benefit of this disclosure.

The auger screw transfers the composition from the holding vessel intothe applicator devices. FIGS. 4 a and 4 b depict a typical fixture thatmay be used to hold applicator devices such a syringes during thefilling process. Fixture 70, i.e. the syringe loading station, isequipped with syringe holder 72 having multiple syringe receptacles 74,and means for securing the syringes to fixture 70 that includes clampingscrew 76, clamping rod 78, and syringe impingement pin 80. Syringe 82 isplaced within syringe receptacle 74. Each syringe is back-filled withthe same volume of paste in a sequential manner using the apparatusdescribed above. The back-filling operation involves dispensing thecomposition into syringe 82 from the back end of syringe 82. Syringe 82is held in place by clamping screw 76. Upon completion of filling,Syringe impingement pin 80 contacts the external of syringe 82, thuscreating pressure on syringe 82 that results in the separation of thestream of composition between syringe 82 and the port of the fillingapparatus. Fixture 70 then indexes such that next syringe 82 is moved tobe in a filling position. Once filled, the syringe plunger is insertedinto the back end of the filled syringe and advanced to its appropriateposition, followed by capping of syringe 82.

Alternately, the basic design of the means for transfer of the materialinto the device, including securing the syringe, use of the impingementpin to affect separation of the material stream, indexing the multiplesyringes in a vertical motion followed by horizontal motion may beautomated. For example a circular fixture comprising multiplereceptacles may index in a circular manner to provide filling of thedevice.

One skilled in the art may envision other means for manufacturing suchcompositions and filling them into devices. For example, a pumptechnique can be used whereby powder can be added to a re-circulatingloop of foaming solution. The foaming solution may be pumped utilizing alow-shearing pump pump and the powder can be added until the desiredproperties have been achieved. Once the desired ratio of liquid to solidis reached, the gas will be introduced into the re-circulating paste. Achamber can be included to allow for the expansion of the paste. Whenthe chamber is full, such that the desired density is reached, thefoamed paste can be continuously filled into syringes.

Given that the density of the flowable hemostatic composition is anindicator of acceptable mechanical and hemostatic properties of thecompositions, the density of the flowable hemostatic composition ismeasured upon completion of mixing to ensure acceptable properties. Onemethod of assessing the density used and described herein includessuspending the hemostatic composition in a series of organic solvents ofknown densities or measuring the weight of a known volume of thecomposition, although other methods of measuring density could beutilized. In monitoring the density of compositions in processes of thepresent invention, the density of the flowable hemostatic composition isassessed by using inert organic liquids with known densities. Theliquids are selected such that any possible interactions with thecompositions will have no impact on the measurements. The choice of thesolvent density coincides with the predetermined acceptable densityrange of the hemostatic composition. The composition is placed in aseries of solvents of varying densities and the density of thecomposition determined based on whether it sinks or floats in thesolvent.

The hemostatic compositions prepared as above are transferred into amedical device as described above and the device containing thehemostatic composition is sterilized, preferably by ionizing radiation.More preferably, sterilization is by gamma irradiation as exemplifiedherein.

While the following examples demonstrate certain embodiments of theinvention, they are not to be interpreted as limiting the scope of theinvention, but rather as contributing to a complete description of theinvention.

EXAMPLES

Samples prepared in the examples below were tested for peak expressionforce as determined using a Chatillon TCD 200, using a 50-lb load cell[DFG 550] at a speed of 2 inches/minute. An in-dwelling catheter sheath(size 12-14 gauge) was attached to the sample syringe to be tested. Thesyringe then was inserted into a holding apparatus, which then wasloaded onto the test instrument. The peak expression force was noted.

Example 1

A total of ten samples were prepared as follows. One gram of drySurgifoam® powder was placed in a plastic container and mixed with 4 mlof saline. The container was capped and the contents were shaken until asubstantially homogenous paste of uniform consistency was obtained. Thepaste was formed into a cylindrical shape and placed into a 10 cc BDpolypropylene disposable luer syringe. The syringes were then capped andfive of the filled syringes were sterilized by gamma irradiation at adose of 25 kGy. The Peak Expression Force was determined and presentedin Table 1. Unsterilized samples are designated as 1a and sterilizedsamples are designated as 1b.

At total of 10 samples were prepared as follows. 1 gm of dry Surgifoam®powder was placed in a plastic container and mixed with 4 ml of saline.The container was capped and the contents were shaken until asubstantially homogenous paste of uniform consistency was obtained. Thepaste was formed into a cylindrical shape and placed into a 10 cc BDpolypropylene disposable luer syringe. A second 10 cc BD luer syringecontaining 3 ml of nitrogen then was connected to the syringe containingthe paste such that the paste could be passed from syringe to syringe.The paste and gas were extruded back and forth between the syringes tothoroughly mix and disperse the gas throughout the paste until asubstantially homogeneous foam-like composition of uniform consistencywas obtained. The syringes were then capped and five of the filledsyringes were sterilized by irradiation at a dose of 25 kGy. The PeakExpression Force was determined and presented in Table 1. Unsterilizedsamples are designated as 1a′ and sterilized samples are designated as1b′.

Example 2

A total of ten samples were prepared as follows. A saline solutioncontaining 0.005% by weight of benzalkonium chloride and 5% weight ofglycerol was prepared. This solution was used to prepare homogenousgelatin-powder pastes as described in Example 1. The paste was formedinto a cylindrical shape and placed into a 10 cc BD polypropylenedisposable luer syringe. The syringes were then capped and five of thefilled syringes were sterilized by irradiation at a dose of 25 kGy. ThePeak Expression Force was determined and presented in Table 1.Unsterilized samples are designated as 2a and sterilized samples aredesignated as 2b.

A total of ten samples were prepared as follows. A saline solutioncontaining 0.005% by weight of benzalkonium chloride and 5% by weight ofglycerol was prepared. This solution was used to prepare homogenousgelatin-powder pastes as described in Example 1. A second 10 cc BD luersyringe containing 3 ml of nitrogen then was connected to the syringecontaining the paste such that the paste could be passed from syringe tosyringe. The paste and gas were extruded back and forth between thesyringes to thoroughly mix and disperse the gas throughout the pasteuntil a homogeneous foam-like composition of uniform consistency wasobtained. The syringes were then capped and five of the filled syringeswere sterilized by irradiation at a dose of 25 kGy. The Peak Expressionforce was determined and presented in Table 1. Unsterilized samples aredesignated as sample 2a′ and sterilized samples are designated as 2b′.

TABLE 1 Peak Expression Force Samples pounds (n = 5) Samples 1a 21.8Samples 1b 26.4 Samples 1′a 12.0 Samples 1′b 21.0 Samples 2a 17.2Samples 2b 22.4 Samples 2′a 11.8 Samples 2′b 16.8

As the data in Table 1 indicates, the inclusion of the gaseous phasehomogenously dispersed throughout the paste significantly reduces thepeak expression force of the composition prior to sterilization comparedto pastes that do not include the homogenously dispersed gaseous phaseor other additives. Consequently, the sterilized composition includingthe homogenously dispersed gaseous phase exhibits an expression forcesignificantly less than that of a sterilized paste that does not includethe homogenously dispersed gaseous phase. In fact, the sterilizedcomposition including the gas phase approximates the expression force ofthe pre-sterilized paste containing no gaseous phase or additives. Thus,a fully sterilized composition may be provided with flowability and/orinjectability, as evidenced by peak expression force, equal to or betterthan that of an unsterilized paste containing no gaseous phase oradditives, which is beneficial to health care providers at the point ofuse. The use of additives, e.g. benzalkonium chloride and glycerol, maybe used to further enhance the properties of the compositions of thepresent invention upon sterilization.

Example 3

25 grams of Surgifoam® gelatin powder were mixed with 125 ml of normalsaline containing 0.005% benzalkonium chloride and 5% glycerol, based onweight of saline, until a uniform paste was formed. The resulting pastewas loaded into a ½ pint Donvier mixer fitted with a mixing paddle. Atube connected to a nitrogen source was fitted through the lid of themixer and the system “closed” to the environment by wrapping in a film.The system was purged with nitrogen for 20 minutes. The paste was thenmixed to homogenously incorporate the nitrogen by rotating the paddlerapidly by hand. Mixing was terminated when the composition filled theavailable volume, indicating homogeneous distribution of the gas phase.The composition was loaded into a 60 cc syringe and subsequentlydispensed into 10 cc BD luer syringes via a two-way luer connector. Thedensity of the composition was approximately 0.7-0.75 grams/ml. Thesyringes were then capped and some of the filled syringes weresterilized by irradiation at a dose of 25 kGy.

Example 4

2.5 liters of normal saline containing 0.005% benzalkonium chloride and5% glycerol dissolved therein, based on the weight of saline, were addedto a 2-gallon double planetary Ross mixer and mixed at maximum speedwith a first portion of nitrogen for 5 minutes to form a foamed liquid.500 grams of gelatin powder and the balance of nitrogen were added tothe foamed liquid over a 12-minute time period with continuous mixing.The composition was mixed for a further 10 minutes after all of thepowder and gas was added. The density of the resulting composition was0.6 grams/ml. The composition was dispensed into 12 cc Monojectsyringes.

Example 5

One-gram samples of Surgifoam® gelatin powder each were mixed with 5 mlof a saline solution containing 0.005% benzalkonium chloride and 5%glycerol to form uniform pastes. The resulting paste was back-loadedinto 10 cc BD luer syringes. All air was extruded from the syringes,leaving the paste packed in the syringe. The first set of syringes wasirradiated with no gas incorporated therein and designated as sample 5a.A second set of samples was prepared by dispensing 3 ml of nitrogen intothe syringes containing the uniform paste. The syringes were cappedwithout further mixing and then stored at 4° C. The samples weredesignated as samples 5b. The third set of samples were prepared byextruding the paste back and forth between the first syringe and asecond syringe containing 3 ml of nitrogen until all of the nitrogen washomogenously incorporated into the paste. The fill-volume of theresulting homogeneous compositions was approximately 9 ml and thedensity of the composition was approximately 0.7 grams/ml. The syringeswere then capped and some of the pre-filled syringes were sterilized byirradiation at a dose of 25 kGy. The Peak Expression Force of the threesets of samples was determined and presented in Table 2.

TABLE 2 Peak Expression Force Samples pounds (n = 5) Sample 5a 21.7Sample 5b 20.7 Sample 5c 15.5

As the data in Table 2 indicates, homogeneous distribution/dispersion ofthe gas throughout the paste is essential to reduce the peak expressionforce of the composition prior to irradiation and to maintain the lowerpeak expression force of the composition after irradiation, compared topastes containing no gas or having gas poorly or partially dispersedthere through.

Example 6

One gram of Surgifoam® gelatin powder was mixed with 5 ml of normalsaline to form a uniform paste. The resulting paste was back-loaded intoa 10 cc BD luer syringe. All air was extruded from the syringe leavingthe paste packed in the syringe. A second set of 10 cc syringescontaining nitrogen with volume ranging from 1 ml to 4 ml, respectively,was fitted to the first via a two-way luer connector. The paste wasextruded into the gas and then passed back and forth between the twosyringes until all of the gas was homogeneously incorporated into thepaste. The fill-volume of the resulting composition was approximately6-10 ml and the density was approximately 0.60 to 1.0 grams/ml, eachdepending on the volume of gas introduced into the paste. The syringeswere then capped and some of the pre-filled syringes were sterilized byirradiation at a dose of 25 kGy.

Sterilized samples were noted as samples 6a through 6e, respectively.The Peak Expression Force of the sterilized samples was determined andpresented in Table 3.

TABLE 3 Gas Density Peak Volume (g/ml) Expression Force Samples (ml)(Pre-sterilized) pounds n = 5 Sample 6a 0 1.00 14.8 Sample 6b 1 0.8612.9 Sample 6c 2 0.75 10.6 Sample 6d 3 0.66 8.6 Sample 6e 4 0.60 8.0

Example 7

One gram of Surgifoam gelatin powder was mixed with 5 ml of normalsaline to form a uniform paste. The resulting paste was back-loaded intoa 10 cc BD luer syringe. All air was extruded from the syringe, leavingthe paste packed in the syringe. A second set of 10 cc syringescontaining air with volume ranging from 0 ml to 4 ml, respectively, werefitted to the first syringe via a two-way luer connector. The paste wasextruded into the gas and then passed back and forth between the twosyringes until all of the gas was homogenously incorporated into thepaste. The fill-volume of the resulting composition was approximately6-10 ml and the density was approximately 0.60 to 1.0 grams/ml, eachdepending on the volume of gas introduced into the paste. The syringeswere then capped and some of the filled syringes were sterilized byirradiation at a dose of 25 kGy. Sterilized samples were noted assamples 7a through 7e, respectively.

The Peak Expression Force of the sterilized samples was determined andpresented in Table 4.

TABLE 4 Gas Density Peak Volume (g/ml) Expression Force Samples (ml)(Pre-sterilized) pounds n = 5 Sample 7a 0 1.00 14.8 Sample 7b 1 0.8611.0 Sample 7c 2 0.75 10.9 Sample 7d 3 0.66 10.1 Sample 7e 4 0.60 10.0

Example 8 Hemostatic Performance of Different Materials in PorcineSplenic Biopsy Punch Model

A porcine spleen biopsy punch model was used for evaluation of thehemostatic properties of samples prepared in Examples 1 through 7 and 9.A 6-mm biopsy punch was used to cut a tissue flap 3 mm deep. The tissueflap was cut out and 0.4 ml of the test materials was applied to thewound site. Manual compression was held over the wound site for 2minutes. The wound site was then observed for up to 3 minutes for signsof bleeding. If bleeding was observed, additional applications of manualcompression for 30 seconds each time were used until complete hemostasiswas achieved. Table 5 lists the results of the evaluation. Results forunsterilized or sterilized samples are represented as an average valuesfor all samples tested.

TABLE 5 Number of Time to Hemostasis Samples Compressions (min:sec)Samples 1a 3 3:35 (n = 2) Samples 2a 3 3:33 (n = 2) Samples 1b 1 2:00 (n= 3) Samples 2b 2 3:00 (n = 6)

Example 9

Two vials of lyophilized Bovine thrombin (20,000 units Thrombogen JJMI)were reconstituted in 20 ml of saline to provide a working solution of1000 u/ml. Clotting activity was measured in an in vitro test asdescribed in Example 10. One vial of this material was stored at 4-8° C.and the clotting activity measured at day 1, day 8 and day 30,respectively. The second vial was sterilized by gamma irradiation (25kGy) and the clotting activity measured as above. The unsterilized andsterilized samples were designated samples 9a and 9b, respectively. Bothsterilized and unsterilized samples were stored at 4-8° C. betweenmeasurements.

Another 2 vials of 20,000 units of lyophilized bovine thrombin werereconstituted in saline containing 0.005% benzalkonium chloride and 5%glycerol. One vial was stored at. 4-8° C. and the clotting activity wasmeasured at day 0, day 1, day 8 and day 30. The second vial wassterilized by gamma irradiation (25 kGy) and the clotting activitymeasured as above. In between measurements both the sterilized andunsterilized samples were stored at 4-8° C. The unsterilized andsterilized samples were designated samples 9c and 9d, respectively.

Several samples of gelatin paste containing the thrombin noted abovewere prepared by mixing 1 gram of Surgifoam gelatin powder with 5 ml ofthrombin solution. The resulting paste was loaded into a 10 cc syringe.Samples were then either sterilized at 25 kGy followed by storage at4-8° C., or stored unsterilized at 4-8° C. Samples so prepared aredesignated and identified below.

Sample 9e=1 g Surgifoam® powder plus 5 ml of sample 9a; SterilizedSample 9f=1 g Surgifoam® powder plus 5 ml of sample 9a plus 3 mlNitrogen: Foamed and SterilizedSample 9g=1 g Surgifoam® powder plus 5 ml of sample 9c; UnsterilizedSample 9h=1 g Surgifoam® powder plus 5 ml of sample 9c; SterilizedSample 9i=1 g Surgifoam® powder plus 5 ml of sample 9c plus 3 mlNitrogen; Foamed and Sterilized

Example 10

Measurement of Thrombin activity by an in vitro coagulation test in aFibrometer instrument (BBL)

Serial dilutions of test sample containing thrombin were prepared inVeronal buffer pH 7.2. 0.2 ml of pooled normal plasma (Citrol Level 1control plasma-Dade Diagnostics) was warmed to 37° C. in the fibrometerincubator block. 0.1 ml of pre-warmed sample dilution was added to theplasma and the timer started simultaneously. The time to clot formationwas recorded. All samples were tested in duplicate and an averageclotting time calculated. Data was graphed as the log₁₀ dilution vs.log₁₀ clotting time and a regression analysis performed. Freshlyprepared thrombin was considered to have 100% activity and all othersamples were calculated as a percentage of the activity relative to thefreshly prepared thrombin. Results are presented in Table 6 and Table 7.

TABLE 6 Effect of Storage time on Thrombin Activity: Stabilization byFormulated Gelatin Paste Storage Solution Percent Loss in ThrombinActivity (Stored at 6° C.) Time 0 Day 1 Day 8 Day 30 9a 0 0 53.3 90.8 9c0 NA 41.1 82.9 9g 0 0 0.8 0

TABLE 7 Effect of Gamma Irradiation on Thrombin Activity: Stabilizationby Formulated Gelatin paste Media for Sterilized % Loss in Thrombin *Samples Thrombin (5 ml/g gelatin Activity powder-25 kGy Dose) Day 6 Day20 9b 100 100 9d 96.0 100 9e 72.6 NA 9f 66.8 56-72 9h 79.2 ND 9i 63.861-73

TABLE 8 In vivo Hemostasis Performance of Pre-filled Thrombin/GelatinPaste Number of Time to Hemostasis TIME: Sample Compressions (min:sec)Day 0: 9g 1 0:30 Day 42: 9g 1 0:30 Day 42: 9g 1 0:30 Day 42: 9h 1 0:30Day 42: 9h 1 0:30

Example 11

One liter of a saline solution containing 0.005% by weight ofbenzalkonium chloride and 5% weight of glycerol were poured into amixing vessel (Ross Mixer, Model DPM2, Serial #75308) and the mixerblades engaged in an operating mode. Nitrogen gas was introduced intothe solution via a tube connected to a nitrogen source in a continuousbubbling manner. The mixture of solution and gas was stirred at 70 Hzfor approximately 10 minutes in order to form a foam as described hereinabove. The addition of the solid particles was commenced after formationof the foam using an addition-funnel attached to the entry port of themixing vessel. 200 grams of gelatin powder were added over a time periodof about 3 minutes. The mixing was continued for about 15 minutes aftertotal powder addition at 70 Hz, followed by additional mixing for about2 minutes at a reduced blade speed of about 12 Hz. Upon completion ofthe mixing, the density of the composition in the mixing vessel wasmeasured using the solvent method as described above to ensure that thedensity was within acceptable parameters, indicating a substantiallyhomogenous dispersion of the particles in the foam.

The composition was transferred to the desired level in the holdingvessel of the filling apparatus equipped with an auger having 7 flights.The distance between the flights at the upper portion of the screw wasabout 3.75 cm, while the distance between the flights at the lowerportion of the screw was about 1.5 cm. The composition then wasdispensed into syringes by way of the auger screw. Approximately 6milliliters (ml) of composition was placed in each syringe. The fillingwas performed using the syringe filling apparatus at a rate ofapproximately 36 ml/minute to about 72 ml/minute. The holding vessel wasreplenished with fresh flowable hemostatic composition as the levelgradually decreased. Upon completion of the filling procedure, thedensity of the flowable hemostatic composition in the syringe wasmeasured as described above. Results are reported in Table 9.

Example 12

Two liter of a saline solution containing 0.005% by weight ofbenzalkonium chloride and 5% weight of glycerol were poured into amixing vessel (Ross Mixer, Model DPM2, Serial #75308) and the mixerblades engaged in an operating mode. Nitrogen gas was introduced intothe solution via a tube connected to a nitrogen source in a continuousbubbling manner. The mixture of solution and gas was stirred at 70 Hzfor approximately 10 minutes in order to form a foam as described hereinabove. The addition of the solid particles was commenced after formationof the foam using an addition-funnel attached to the entry port of themixing vessel. 400 grams of gelatin powder were added over a time periodof about 5 minutes. The mixing was continued for about 10 minutes aftertotal powder addition at 70 Hz, followed by additional mixing for about2 minutes at a reduced blade speed of about 12 Hz. Upon completion ofthe mixing, the density of the composition in the mixing vessel wasmeasured using the solvent method as described above to ensure that thedensity was within acceptable parameters, indicating a substantiallyhomogenous dispersion of the particles in the foam.

The composition was transferred to the desired level in the holdingvessel of the filling apparatus equipped with an auger having 7 flights.The distance between the flights at the upper portion of the screw wasabout 3.75 cm, while the distance between the flights at the lowerportion of the screw was about 1.5 cm. The composition then wasdispensed by way of the auger screw. Approximately 6 milliliters (ml) ofcomposition was dispensed into each syringe at a rate of approximately120 ml/minute. The holding vessel was replenished with fresh flowablehemostatic composition as the level gradually decreased. Upon completionof the filling procedure, the density of the flowable hemostaticcomposition in the syringe was measured as described above. Results arereported in Table 9.

TABLE 9 Effect of filling rate on the density of paste Density of Paste(gm/ml) Syringe Rate of filling Number 12 ml/min 18 ml/min 36 ml/min 72ml/min 120 ml/min 1 <0.659 <0.626 <0.626 <0.626 <0.626 10 <0.695 <0.626<0.626 <0.626 <0.626 15 <0.703 <0.703 <0.626 <0.626 20 <0.703 <0.703<0.626 <0.626 25 <0.703 <0.703 <0.626 <0.626 30 <0.718 <0.703 <0.659<0.626 35 <0.745 <0.718 <0.659 <0.626 40 NA <0.718 <0.659 <0.626 50 NANA <0.659 <0.626 <0.626 60 NA NA <0.703 <0.659 80 NA NA <0.703 <0.659100 NA NA NA <0.703 <0.626 120 NA NA NA <0.703 140 NA NA NA <0.703 150NA NA NA <0.703 <0.626 600 NA NA NA NA <0.626 * Density of pastemeasured as extruded out of the Auger. Each exudate is approximately 6ml in volume.

Table 9 demonstrates the effect that the rate of filling may have on theresulting density of the paste. It first is noted that for a particularrate of filling, i.e. number of syringes filled per minute, the densityof the composition indicated to be less than a particular value for theparticular number of syringe is greater than the density value measuredat the previous number of syringe. For example, at 12 ml/minute, thedensity of the composition in the 25^(th) filled syringe is less than0.703 but greater than 0.659. It is noted that at higher filling rates,the consistency of the composition may be maintained within acceptableparameters over longer periods of time. As noted, at a higher fillingrate, e.g. 72 ml/minute, the density of the composition is maintained tobe no greater than 0.703 g/ml at the 150^(th) syringe filled, while at afilling rate of 12 ml/minute, the same relative change in the density ofthe composition is noted at the 25^(th) syringe filled. It is noted thatthe particular rates of filling noted herein are applicable to theparticular apparatus and compositions disclosed herein and may in factvary depending on apparatus design and composition.

1-19. (canceled)
 20. A medical device suitable for applying a flowable hemostatic composition to a site requiring hemostatis, said device having disposed therein a substantially homogeneous hemostatic composition, said substantially homogeneous hemostatic composition comprising: a continuous, biocompatible liquid phase, a solid phase comprising particles of a biocompatible polymer suitable for use in hemostasis and which is substantially insoluble in said liquid phase; and a discontinuous gaseous phase comprising a biocompatible gas, said continuous liquid phase comprising said solid phase and said discontinuous gaseous phase substantially homogenously dispersed there through, wherein the ratio of said liquid phase, said solid phase and said gaseous phase is effective to provide said composition with hemostatic properties.
 21. The device of claim 20 wherein said liquid phase comprises saline.
 22. The device of claim 20 wherein said biocompatible polymer is selected from the group consisting of proteins and polysaccharides.
 23. The device of claim 22 wherein said protein is selected from the group consisting of gelatin, collagen, fibrinogen and fibronectin.
 24. The device of claim 23 wherein said protein comprises gelatin.
 25. The device of claim 20 wherein the average diameter of said particle is from about 40 to about 1200 microns.
 26. The device of claim 20 wherein said particles, said continuous liquid phase and said gaseous phase are present in said substantially homogeneous hemostatic composition at a ratio of from about 1:2:1 to about 1:12:13, based on g:ml:ml.
 27. The device of claim 20 wherein the density of said substantially homogeneous hemostatic composition is from about 0.9 g/mil to about 0.3 g/ml.
 28. The device of claim 20 wherein said gas is selected from the group consisting of air, nitrogen, carbon dioxide, xenon and argon.
 29. The device of claim 20 wherein said composition further comprises a functionally effective amount of an additive selected from the group consisting of antimicrobial agents, foaming agents, foam stabilizers, surfactants, antioxidants, humectants, thickeners, lubricants, diluents, wetting agents, irradiation stabilizers, plasticizers, heparin neutralizers, procoagulants and hemostatic agents.
 30. The device of claim 28 wherein said composition comprises up to about 20 weight percent of glycerol, based on the weight of said liquid phase.
 31. The device of claim 28 wherein said composition comprises up to about 1 weight percent of a quaternary amine, based on the weight of said liquid phase.
 32. The device of claim 28 wherein said composition and said device are sterile.
 33. The device of claim 28 wherein said composition and said device are sterile.
 34. The device of claim 29 wherein said functional additive is selected from the group consisting of fibrinogen and thrombin. 